Electric machine construction



Feb. 9,' 1954 D. w. BLOSER 2,668,925

ELECTRIC MACHINE CONSTRUCTION Filed April 5, 1949. 2 Sheets-Sheet 1 DWIGHT 14 54 0.558

A rraeMs-y Feb. 9, 1954 D. w. BLOSER 2,668,925

ELECTRIC MACHINE CONSTRUCTION Filed April 5, 1949 2 Sheets-Sheet 2 Avmvvrae 25 DIV/6197'. IV. 620.55,?

Patented Feb. 9, 1954 E-EECTRIEJ MKGHINE CONSTRUCTION Dwightwlflloser west Englewood",.N.l.I., assignor. to KearfottOompany,.Inc;, New York, N. Y., a.

corporation'of NewYork Application April; 5, 1949-, Serial No. 85,645

3 Claims. L.

'Ihe. present. invention relates to}. electric; mas chines suchzas. motors; generators, and synchro units. and more particularly to). the high; quality. smallamachine field.

Small machines. ofi high performance. charac teristics are used extensively in servo y systems. in: environments; se1'iously='-limiting;- thein weightpand dimensionsvyetz demanding relatively high rotor; torque:

Itiiisawell known that the-:torque-of a=.-dynamo.-- electric machine variesinversely: with the.- square: ofithe'zair; gap. length andydirectly with: theaxial widthsof; thee aingam The? width" Oil. the air. gap: is; limited by: the. permissible: over-all machine lengths Heretofore practical minimizing; ofv the. air: gap length haspbeeni limited-11m manufacture by the dimensional-i tolerancesv required: for: thecomponents; from: they: rotonshaftradially? out to:=the.-inside ofthehousing: These'atolerances being: cumulative have..=placecl.:-.apracticallimitatiom on the minimum: length. Ofr air" gaps. sincewthe airgaprlength must: be suflicientto; allow for-r the dimensionab variations of rotors. and stators within; manufacturing tolerances so as.- to. pres vent contact between stator and; rotor. during;

use;

It isan object oft-hezpresentiinvention to providera; novel construct-iom that obviates the-need to observe certain conventionali. dimensional. parts. tolerances inrmanufacturei It is a further objector. theepresentinvention tQr providea novelmethod. of. manufacturing electric machines which simplifies themanufaca turing, processes, yeti results-, in. a. machine: of. greatly improved torque. characteristics...

Other. obj ectsof; the-presentinventioninclude.

theprovision of a novel construction; which permits the massproduction; of: rotating electr-"ic. machines-sci. improved torque.- characteristics and; the provision of a unique.--.methodi of. assembly whereby;- the air:- gap. length isminimized andconstruction-is simplified.

Qthe-r. obj eats-rot. the; present. invention-will. be, come Welh understood; from; ai'study of: theefola lowing. description; in conjunction withwthe: at. tached. drawings,-.. throughout which. like. nu-

- m erals refer, tolike :part'sr Fig. l is.anielevationalvviewof a-.motor: made in accordance with thelpresent invention;

Fig. enlargedi end. elevational-..vieiw of. the motor Fig. 3'. is a longitudinal; sect-ional View. taken alongthe'tline. 3-3 oiFig... 2;

Fig. .4 isga longitudinal;v sectional viem'ofJthe: motor. with; endlplate. andlmt L removedi 2 Having reference particularlyto Fig 3, Ill-rep.- resents a-motor having two main housing. sections, H and L2. The stator includesastaclsof. iron. laminations l3; and windings l4 distributed through the lamination stack inthe conventional.

manner. Housing. section N is generally cup shaped having an end plate I5 and an integral; cylindrical. portion it. End plate. t5-hastapped holes Mia and a pilotflange libior mounting the motor to a. wall orbulkhead; End plate- [Br-also: merges into i an internally extending hub. portiom H. A.- metal ring Hie is spotweldedwithinsend plate i5 and protects the machinewindings-fronr being damaged; Housing section t2 includestan end; plate l8: and a cylindricalportion; I9 inter. fitting with portion it of section II. Section: Hi also has a cylindrical hub portion 20 extending: inwardly of end plate'portion t8: Housing? sect-i'ons l and'l2 are secured togetherby the spun. over-"lip 27 of section H.

End plate H3 encloses an insulating bushing; ring 22into'which'are screwed: electrical connec tors 23* and cover plate bolts 23. extending through cover plate ii'i. I-I-ubportions Ma and w'terminater inwardly in radial, annular'faces: 24 and 25 respectively. Housing" section H has: formedstherein a shoulder 26.. It willbe noticed thatishoul'der 26: lies to the left (Fig; 3) ofith'et plane; containin'g'annular face 24: Likewisegit: willbe noticed that cvlindricalportioni I9 of. housing section l2 terminates in a radial-plane to the right of the plane containing annula-rrface 25; These annular faces- 2t and 25 butt against the'end'laminations of stack is: and keep-themi rigidlyin position when. the two housing sectionsit and. i2 are fitted together and retained-int place by the lip 2-1.

Windings Mare covered by a protectivepaper. coveringZ'l, which may be: of fiat-stock or. pre:-' shaped". to fit. over windings Ill.v Electrical connections are brought out through covering: 21:

to connect. winding I4- and connectors 23; by,"

means of. leads 28. Stator laminations [-3 have; an outsidediameter smaller, by about .004 than the. internal diameter of portion. lti'ofa the housing H, leaving an annular space 29rbetweenxthe2 housing H5 and. the laminations It: This an:-- nular. space. is exaggerated in the drawings-.for clarity.

Rotor. 3t, which may be.- of conventionalcon.

struction, is carried. on. a shaft.- 31; through ball:-.

exceeding the scope of the invention, which is to be limited only by the scope of the appended claims.

What is claimed is:

1. A dynamo-electric machine comprising a housing containing a stator and a rotor, said housing having a longitudinally extending generally cylindrical portion terminating at each end in inwardly extending radial hub members, said stator being spaced from the longitudinally extending housing portion, bearing members mounted in axial alignment within said radially extending portions, said rotor beingmounted within said bearing members and having a central shaft extending outside said housing, said stator including a stack of laminations of magnetic material and a distributed winding, said hub members extending axially inwardly and being in close contact with the end laminations of said stack and forming with said longitudinally extending portion a closed chamber, a coverplate attached to one of said radially extending housing sections, said coverplate having electrical terminals mounted thereon, electrical leads extending between said winding and said terminals and an envelope of solid impregnating compound between said housing and said stator and completely filling said chamber and supporting said stator within said housing.

2. A dynamo-electric machine comprising a housing containing a stator and a rotor, said housing having a longitudinally extending generally cylindrical portion terminating in inwardly extending radial hub portions, said stator being spaced from the longitudinally extending housing portion, bearing members mounted in axial alignment within said radially extending hub portions, said rotor being mounted within said bearing members and having a central shaft extending outside said housing, said stator including a stack of laminations of magnetic material having a centrally located rotor receiving bore and a distributed winding, said hub portions and said centrally located bore having the same diameter, a coverplate attached to one of said radially extending housing sections, said coverplate having electrical terminals mounted thereon, electrical leads extending between said winding and said terminals and an envelope of solid impregnating compound between said housing and said stator throughout said longitudinally extending portion of said housing and within said inwardly extending hub portions.

3. A dynamo-electric machine comprising a housing containing a rotor and a stator including a stack of laminations and a winding, said stack of laminations having a central, rotorreceiving bore formed therein, said housing having an axially extending portion spaced from said stack of laminations and terminating in end sections having hub members with a rotor-receiving bore formed therein, said hub members extending axially inwardly and contacting the end laminations of said stator forming with said axially extending portion a closed chamber, bearing members mounted within said hub members in axial alignment and a rotor-carrying shaft mounted in said bearing members, and an envelope of solid impregnating compound within said closed chamber and extending between the interior of said housing and said stack of laminations and supporting said stack within said housing.

DWIGHT W. BLOSER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,425,308 Woock et al. Aug. 8, 1922 1,852,829 Welch Apr. 5, 1932 2,107,481 Johnson Feb. 8, 1938 2,123,933 Cotterman July 19, 1938 2,311,805 Yost Feb. 23, 1943 2,329,151 Brady Sept. 7, 1943 2,423,345 Roters July 1, 1947 2,483,024 Roters Sept. 27, 1949 21,485,408 Pezzillo Oct. 18, 1949 FOREIGN PATENTS Number Country Date 137,089 Great Britain Dec. 22, 1919 

